Because most school data loggers are able to run on Windows 98 (or even Windows 95) they do not need to be connected to the latest computers. Most will run very well on a Pentium 200MMX level computer with 32 Mbyte of RAM. Things to consider;

most data loggers can log seismograph data every 1 second but reducing this to once every 5 or 10 seconds (or minute for Data Harvest) will give an old computer more time to think and require less storage space

older computers are less tempting for "idle hands"

in "Control Panel" in Windows it is possible to turn off screen savers

old monitors do not have screen saver mode and so will always stay on

reformat the hard disk to get rid of any old files

clean out any dust in the Pentium CPU fan to keep it cool. Remember it stays on 24 hours a day.

unless you want to make earthquake files available live over the school network or on the internet there is no advantage having computer on the network.

if you do use a networked computer remember that the whole network is very tempting for 'idle minds". If you use a student level password for the seismograph program this limits access to other programs on the computer or network.